Kidney stone pain. Help!

SATYENDRA PERSAUD

KIDNEY stones are very common in TT and by extension, so is stone pain (called renal colic). Among persons who have experienced both, the comment is often made that renal colic is worse than labour pains.

How does renal colic present?

The pain is usually excruciating and usually feels like it is in the back going towards the groin. As the stone moves through the tract, the location of the pain may change. Renal colic comes on in waves and the patient often feels unable to lie still. This pain may be accompanied by nausea and vomiting and there is often blood in the urine. As the stone is about to enter the bladder, patients often complain of having a sensation to urinate very often but nothing comes – this is due to irritation. In infected cases, patients may have fever and chills and this is very serious.

Not all back pain is due to kidney stones

Most people automatically ascribe back pain to kidney stones but a number of conditions may cause pain in the back. Mechanical back pain is common and patients note pain with activity and may even have radiation down the legs. Appendicitis and gallstones may also mimic kidney stones. In women, tubal pregnancies may cause similar symptoms and in men, testicular problems may also cause acute back pain. Inflammation and other conditions of the colon may present in similar fashion as can swellings (aneurysms) of the aorta. This is why it is important for your doctor to take a good history and examine you properly.

How is suspected colic treated?

You will need medication for the pain and the most useful class of drugs is the NSAID group which includes drugs such as ibuprofen and diclofenac. Sometimes the pain may be so severe that opiates like morphine may be necessary. You may also require medication to help with vomiting. If you have fever and sepsis, you will need urgent antibiotics and special culture tests of the blood and urine looking for bacteria. You will also require basic blood tests to look for inflammation and to test your kidney function and blood sugar. You will need imaging to confirm that you have stones or whether your pain may be due to something else. The best investigation to look for stones is a CT scan as this is more accurate than an ultrasound and gives us much more information. You may also require an X-ray.

What next?

If your pain settles and your stone is in the urine pipe on the way down to the bladder, you may be allowed to pass it naturally with a repeat scan or X-ray in a few weeks. Not all stones can be allowed to pass in this way – they should be under one centimetre with no pain or signs of infection before this is allowed. You may be prescribed certain medication to aid passage. If your pain does not settle or if you show signs of infection or kidney damage, you will require admission. If your kidney is swollen and infected due to the stone, this is an emergency. In these cases you will require placement of a stent (a thin plastic tube) into the ureter (kidney pipes) or a thin tube called a nephrostomy is placed through the skin directly into the kidney. The stent is placed through the urine passage with the aid of cameras – no cut is made. The purpose of these two procedures is to drain the infected kidney. Definitive treatment will take place once you have recovered from the infection. Stents on their own are not definitive treatment for stones and need to be changed every few months until your stone is treated. We discussed treatment options in a previous article. If you have a stent in and it has been more than six months since it was last changed (unless it is an annual stent) please check with your urologist.